The Best Radon Test Kits

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According to the Environmental Protection Agency, one in 15 homes in the U.S. has radon at levels high enough to be a health concern. Exposure to radon over long periods of time causes lung cancer. Over 21,000 deaths are attributed to radon exposure annually.

Three types of simple home radon gas test kits are available throughout the country. These types are short-term, long-term and digital readouts. The short- and long-term kits must be sent to a lab for analysis, while the digital type provides an instant readout.

Short -Term

Short-term radon kits are the least accurate type. However, they are useful in applications where you need results quickly. Typically, short-term tests need three to five days of exposure and additional time for mailing and lab reports. Short-term kits use a charcoal canister that traps radioactive radon particles from the air. The analysis determines the radon picocuries per liter of air.

Consumer reports analyzed home radon test kits in 2008, and gave the Radon Testing Corporation of America’s short-term test kit the highest rating for accuracy. RTCA results were closest to the calibrated monitor used for comparison. RTCA provides two bar-coded canisters and a prepaid postage return label; lab fees are included in the May 2010 price of $44.85. RTCA test kits are analyzed the same day they are received, and you can get results by phone, fax or email the same day. RTCA kits are available online.

ProLab radon test kits are available at over 40,000 stores in the U.S., including chain hardware stores, home centers, drugstores and supermarkets. ProLab model RA100 test kits contain two identical desiccated charcoal canisters to expose side-by-side for 96 hours. A silica gel desiccant removes all moisture from the air to improve accuracy. In May 2010, the price at Ace Hardware for the ProLab RA100 test kit was $10.99, with an additional lab fee of $30.00. Turnaround time for results is one to seven business days, with fast email results available in addition to postal return mail. ProLab results are approved for real estate inspections.

Inexpensive AirChek radon test kits are priced at only $11.95 at as of May 2010. This price includes the lab results.

Warning: found that the Accustar CLS 100i and the Kidde short-term test kits inaccurately reported 40 percent lower radon levels than actually existed. Results from two labs concurred.


Radon levels can change during the day as well as from day to day, so a long-term kit is the best choice for an accurate radon reading. Expose long-term kits for three to 12 months before sending them for lab analysis. rated the long-term Accustar alpha track test kit, model AT 100, as reliable and accurate. As of May 2010, it is priced at $50, which includes dual test devices and lab fees.

ProLab Model RL116 long-term radon test kits, available at Ace Hardware, are priced at $29.99 in May 2010. This price includes lab fees and results. offers two long-term test kits. May 2010 prices are $30.71 for the regular alpha track, or $45.38 for the alpha track gold-seal, which is the best accuracy model. Each model includes one test device and lab fees.

Digital Monitor gave a high rating to the Safety Siren III digital monitor, available at in May 2010 for $129.95. It takes continuous air samples and updates hourly. Each device is calibrated at the factory to ensure accuracy. Move the monitor from room to room to test each area of your home. You pay no lab fees, since the unit records the actual radon level. It even runs a daily self-check and alerts you to malfunctions.

Radon in Water

Radon may also be found in groundwater. The EPA recommends annual testing of well water.

RTCA sells a water test kit for $29.95 as of May 2010. The price includes the lab fees and a postage-paid mailing envelope.

The ProLab water radon test kit, model RW103, is priced at $12.99 at Ace Hardware in May 2010. It includes a single vial, and an additional $30 lab fee is required.